The Shape of the Homunculus Nebula around η Carinae

Abstract

AbstractFrom extensive spectroscopic observations we derive the three-dimensional structure of the Homunculus Nebula surrounding η Carinae. The analysis shows that the two lobes are hollow and incomplete, and that the gas was ejected at similar epoch. Consequently the distribution of material we see reflects its initial velocity. Using the observed expansion velocity, and the known time of ejection, we derive a distance to η Car of 2.2 ± 0.2 kpc.